Harry Redknapp was in charge at Spurs for four years between 2008-12 and took an intense interest in Cahill after his performances for Bolton during the 2010/11 season.
Cahill ended up signing for Chelsea where he would win two Premier League titles and the Champions League in a seven-year stint.
"I went to one of those games against Tottenham [for Bolton] and I remember my dad saying afterwards: 'I've got to sign him, he's different class.' Then you went to Chelsea," Jamie Redknapp told Cahill in a video call for the Daily Mail.
He added: "I know for a fact one of my dad's big regrets is missing out on you."